Jamil A.C. Mangan smiles, full of patience, care and grace as he sails through a demonstration of ballroom dance steps.

Over the course of Athol Fugard’s " ‘Master Harold’ … and the Boys" at Luna Stage in West Orange, in which Mangan plays the pivotal role of Sam, that beaming grin gradually dims and eventually gives way to wrenching expressions of pain, fury and regret.

Directed with an eye for detail by Reginald L. Douglas, the play follows a coming-of-age story of the young white boy Hally — or Harold — and his relationship with his two black servants, Sam and Willie.

Hally’s trek into manhood is complicated by shame and love for his father, a disabled alcoholic, who is in the hospital when the play begins.

The action takes place in South Africa during apartheid; the production commemorates the 20th anniversary of Freedom Day, a holiday celebrating the first post-apartheid elections. The play bristles with racial tension as Hally tries to exercise his power over "the boys" for the first time, trying to control what he can as he begins to realize how much of life he cannot.

As Hally, Tony Knotts is the picture of uncontrolled teenage energy and moods, aided by Douglas’ staging, which has him climbing excitedly over furniture one minute and slumping dejectedly at a table the next. His transformation, like Sam’s, unfolds gradually and enthrallingly.

Hally’s discomfort with his station becomes clear as he tries to study. Despite apparent intelligence and the desire to think critically about world issues, or at least to consider himself an intellectual, Hally lacks the attention and drive for school. As Sam reads to him, he balances an impeccably shined knife on his nose.

At first, Hally is unable to stand the thought of human brutality, shrinking as Willie and Sam demonstrate the way black men are beaten in prison.

But as he becomes increasingly distressed, he experiments with his first attempts at cruelty — and they are far from tentative.

At the same time, Sam — the only present fatherly figure — tries to steer Hally toward ideals of beauty, romance and dreams. In part, this is where the dancing comes in, representing "a world where nobody trips or stumbles or bumps into anybody else," or becomes embroiled in conflict.

Willie, meanwhile, who is slightly younger (more like a quirky uncle, and played with eagerness by Beethovan Oden), offsets Sam’s inherent gravity so that the three form a harmonious group as they reminisce about time spent together when Hally was a boy.

It’s Willie who Sam is trying to teach ballroom dance to in advance of a big competition, but Hally gets in on the excitement, at least briefly. The "boys" sing their own music when they can’t afford the jukebox.

Thoughtful set design by Paul Tate dePoo III sets the theater up with seats on three sides to intimate effect, as though we’re in the tearoom where Harold’s mother works along with the characters. Deborah Caney’s costumes draw out Harold’s extravagance and Sam and Willie’s attention to cleanliness and propriety.

Fugard’s play traverses ample ground in about 90 minutes. Some of its early jokes, in which Sam teases Willie about his clumsiness and lack of a dance partner, feel a little rushed in this production, not quite landing to full effect.

But as far as the larger points in the trio’s development are concerned, the drama of the play is fully, witheringly intact.